In general, a cooperation communication scheme is a communication scheme for effectively transmitting signals of a relay in a case of signals with a relatively weak strength due to a great distance between a radio transmitter and receiver. The relay includes a transmitter and a receiver, and may function to receive signals of an original transmitter and re-transmit the received signals, thereby enabling an original receiver to receive signals with a relatively strong strength.
In order to design the above-described cooperation communication system, a multiplexing scheme for removing interferences of signals may be applicable, and confirming whether transmitted signals have been subjected to a re-treatment upon relaying is important.
Conventional cooperation communication schemes may use a half multiplexing scheme or a multiple access scheme to reduce or eliminate interference of the signals. According to the conventional half multiplexing scheme, in a first sub-slot obtained by half-dividing a single time slot, an original transmitter transmits signals and the relay receives the signals, and in a second sub-slot, that is, the remaining sub-slot, the relay transmits the signals and the original receiver receives the signals. In this instance, since the original transmitter does not transmit the signal, the interferences of the signals may be eliminated. According to the conventional multiple access scheme, the interferences of the signals may be alleviated using various schemes as well as a Code Division Multiple Access (CDMA) scheme, and also a relaying and transmitting operation may be performed using a non-orthogonal scheme. The relay may only amplify the received signals to re-transmit the amplified signals, and perform decoding and encoding on the received signals to thereby transmit the decoded and encoded signals. In this instance, the performance may be improved when the decoding is successfully performed, otherwise, the relaying and transmitting operation are not completely performed when the decoding fails.